脑胶质瘤中ppENK基因启动子区的甲基化状态研究

目的 检测脑胶质瘤组织中候选抑癌基因ppENK基因启动子区的甲基化状态,探讨ppENK基因启动子的异常甲基化水平在脑胶质瘤发生发展中的作用以及与临床病理资料之间的关系.方法 采用巢式聚合酶链反应(nested polymerase chain reaction nPCR)方法和亚硫酸氢盐修饰后测序法(Bisulfite sequence polymerase chain reaction BSP),检测32例脑胶质瘤组织和10例正常脑组织中ppENK基因启动子区CpG岛的甲基化状态.结果 脑胶质瘤组织中ppENK基因启动子甲基化率为40.6％(13/32),明显高于正常脑组织中ppENK基因启动子甲基化率0％(0/10),两者差异存在统计学意义(P=0.015).在低级别(Ⅰ-Ⅱ级)组和高级别(Ⅲ- Ⅳ级)组脑胶质瘤中ppENK基因启动子甲基化率分别为21.1％(4/19)和69.2％ (9/13),通过分析表明两者差异存在统计学意义(P=0.006).结论 ppENK基因启动子的CpG岛在脑胶质瘤中存在高甲基化现象,可能与胶质瘤发生有关.ppENK基因启动子的甲基化状态与胶质瘤病理分级有关,与年龄、性别、病理分型无关.

Methylation status of promoter of mismatch repair gene ppENK in glioma

Objective To explore the methylation status of ppENK promoter region in glioma and discuss the abnormal ppENK gene promoter methylation gliomas occurrence and development,the relationship between role and clinical pathological material.Methods Methylation status of the ppENK promoter region was assayed in 32 glioma tissues and 10 normal brain tissues by nested polymerase chain reaction(nPCR) and Bisulfite sequence polymerase chain reaction(BSP).Results BSP showed that the ppENK promoter region was hypermethylated in 13 of the 32 glioma tissues and no methylation of ppENK promoter was detected in the 10 normal brain tissues.The promoter hypermethylation ratio of ppENK gene in glioma tissues(40.6%) was significantly higher than that in normal brain tissues(0%,P=0.015).Moreover,we found that the aberrant promoter methylation of ppENK gene was significantly correlated with tumor grade(P=0.006),but not correlated with age,sex and tumor types of patients(P=0.154,0.961 and 0.694,respectively).The rate(21.1%) of ppENK promoter methylation in grades Ⅰ~Ⅱ gliomas was significantly lower than that(69.2%) in grades Ⅲ~Ⅳ gliomas(P<0.05).Conclusions ppENK promoter(CpG island) hypermethylation exists in glioma,which may correlates with the occurrence of glioma.The expression and promoter region methylation of ppENK gene in the gliomas are related to pathological grades,not related to the patient’s age,gender and tumor size factors.